A single procedure is presented for the determination of eigenvalue and eigenvector derivatives of general eigensystems, including those arising in flutter and divergence analysis. The method requires only the knowledge of the eigensolution under consideration and no information about the transposed problem. In the procedure, the eigenproblem is not presented as such, but as a nonlinear algebraic system of equations with the eigenvalue and the eigenvector as unknowns and the eigenderivatives coming from the solution of a linear system of equations that is determined trivially by differentiati ng the nonlinear equations with respect to a structural parameter. The technique can be extended easily to derivatives of any order and always requires solutions of the same linear system with different right-hand sides. The coefficient matrix of this linear system always maintains the structure of the matrix of the eigenproblem and three methods of solution are presented to take full advantage from its symmetry and sparseness, if present. Application to flutter and divergence problems is emphasized, as the basic idea of the method unifies the determination of a solution and of its derivatives in one single approach.

A new formulation of the flutter equation allowing efficient solutions both by a continuation and a direct method is herewith presented.

Chemischer Informationsdienst. Organische ChemieVolume 1, Issue 38 Natural Products ChemInform Abstract: ISOLIERUNG VON GERMACREN B,BETA-ELEMEN UND ANDERER KOMPONENTEN AUS DEN BLAETTERN VON HEDERA HELIX R. BERNARDI, R. BERNARDISearch for more papers by this authorC. CARDANI, C. CARDANISearch for more papers by this authorA. GHIRINGHELLI, A. GHIRINGHELLISearch for more papers by this authorA. SELVA, A. SELVASearch for more papers by this author R. BERNARDI, R. BERNARDISearch for more papers by this authorC. CARDANI, C. CARDANISearch for more papers by this authorA. GHIRINGHELLI, A. GHIRINGHELLISearch for more papers by this authorA. SELVA, A. SELVASearch for more papers by this author First published: September 22, 1970 https://doi.org/10.1002/chin.197038416Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume1, Issue38September 22, 1970 RelatedInformation

Ants communicate via large arrays of pheromones and possess expanded, highly complex olfactory systems, with antennal lobes in the brain comprising up to ∼500 glomeruli. This expansion implies that odors could activate hundreds of glomeruli, which would pose challenges for higher-order processing. To study this problem, we generated transgenic ants expressing the genetically encoded calcium indicator GCaMP in olfactory sensory neurons. Using two-photon imaging, we mapped complete glomerular responses to four ant alarm pheromones. Alarm pheromones robustly activated ≤6 glomeruli, and activity maps for the three pheromones inducing panic alarm in our study species converged on a single glomerulus. These results demonstrate that, rather than using broadly tuned combinatorial encoding, ants employ precise, narrowly tuned, and stereotyped representations of alarm pheromones. The identification of a central sensory hub glomerulus for alarm behavior suggests that a simple neural architecture is sufficient to translate pheromone perception into behavioral outputs.

It is reported that as of last year, an estimated 627,000,000 component parts have been mechanically assembled into 26,000,000 printed wiring boards. It is stated that the production equipment requirements and desires of the various assemblers of electronics equipment vary from a single bench-mounted inserting machine (for small lots), to the punched-card-controlled automatic-assembly machine, or even the automatic conveyor. It is pointed out that there is no one piece of equipment that will satisfy the needs of all assemblers; but that the DYNASERT system described can satisfy most. The paper includes a discussion of: a) factors governing the choice of a system, b) development of the DYNASERT machine system, including machines for component-part preparation, insertion---4 types, and conveying--up to 48 stations, c) varying the system to meet changing production demands, d) considerations affecting design for mechanical assembly, and e) benefits of mechanized assembly. An account is given of five users, making from 20 to 7000 panels per day, where all showed a considerable saving through mechanization. It is concluded that nearly all assemblers can utilize mechanized assembly to advantage, with the choice and size depending upon many factors. It is stressed that Military designs should be made compatible with mechanized assembly to provide for expansion in a National emergency. Finally, it is emphasized that mechanical assembly offers a means of increasing production in the face of a reduced labor force as related to the increasing popu- lation.